Boosting lithium rocking-chair engineering from the villus cavity and Ni catalytic center of a silicon-carbon anode for high-performance lithium-ion batteries

Generally, the dynamic silicon nanoparticles (Si NPs) cores and static carbon shells of silicon-carbon anode materials mismatch all through the lithiation and de-lithiation of high-capacity Li-ion batteries (LIBs). Herein, we used nickel nanoparticles (Ni NPs) as a catalyst to induce the growth of villus cavity carbon nanotubes (CNTs) inside N-doped hollow carbon nanofibers (NHCF), which was firmly attached to active silicon nanoparticles (Si NPs), building an adaptive conductive and mechanical carbon network (Si@Ni-CNTs@NHCF). The high conductivity of the crustaceous NHCF of Si@Ni-CNTs@NHCF facilitated the carrier transfer. Moreover, the compact villus cavity formed by Ni-CNTs could buffer the volume fluctuations of Si NPs and maintain a conductive connection with the expanding/contracting Si NPs during the charge/discharge process. More importantly, the Ni catalytic activity of Ni-CNTs contributed to the balanced behavior of lithiation and de-lithiation for the improvement of structural compatibility and the long-cycle stability of the electrode. Notably, Si@Ni-CNTs@NHCF, with the current density of 1 A g(-1), had a high reversible capacity of 1072 mA h g(-1) after 1000 extremely long stable cycles. This work deepens our understanding of the structural modification of Si/C anodes by constructing a compatibly conductive, mechanical and catalytic material to achieve stable lithiation and de-lithiation cycling processes.

Automated summary

In this study, nickel nanoparticles (Ni NPs) were used as a catalyst to induce the growth of villus cavity carbon nanotubes (CNTs) inside N-doped hollow carbon nanofibers (NHCF), which were attached to active silicon nanoparticles (Si NPs), forming an adaptive conductive and mechanical carbon network (Si@Ni-CNTs@NHCF). The Ni catalytic activity of Ni-CNTs contributed to the balanced behavior of lithiation and de-lithiation, improving the structural compatibility and long-cycle stability of the electrode. The findings deepen our understanding of structural modification for stable lithiation and de-lithiation cycling processes for Si/C anodes.